To find the probability of an offspring being a short pea plant from a cross between two tall, heterozygous pea plants, we can use a Punnett square.
Let's denote:
- T = tall (dominant)
- t = short (recessive)
Both parents are heterozygous, which means they have the genotype Tt.
Using a Punnett square, we can set it up as follows:
T t
-----------------
T | TT | Tt |
-----------------
t | Tt | tt |
-----------------
From the Punnett square, we derive the following genotypes for the offspring:
- TT (tall) = 1
- Tt (tall) = 2
- tt (short) = 1
This gives us the following ratio:
- Tall (TT or Tt) = 3
- Short (tt) = 1
The probability of obtaining a short plant (tt) is: 1 (tt) out of 4 total possibilities = 1/4 = 25%.
Thus, the probability that an offspring will be a short plant is 25%.